Hey guys! I exported my Products collection to /private/data/Products.json and now I'm getting this error on startup:

WARN Reaction: Error while importing to Products: After applying the update to the document {_id: "4ei6mcXnBRAYy2n48" , ...}, the (immutable) field '_id' was found to have been altered to _id: "J2RFf59kHCPwW844B"

Has any of you already experienced this? What does it mean? J2R[...] is a variant and 4ei[...] is its ancestor